Kite with flexible ballooning sail surfaces



Nov. 26, 1968 c. EJJOHNSON 3,412,964

KITE WITH FLEXIBLE BALLOONING SAIL SURFACES Filed Dec. 27, 1966INVENTOR. Car/ 5 (10/2/7600 wd/M ATTORNEY United States Patent 3,412,964KITE WITH FLEXIBLE BALLOONING SAIL SURFACES Carl Edward Johnson, 322Hill St., Rte. 1, Box 355A, Coloma, Mich. 49038 Filed Dec. 27, 1966,Ser. No. 604,794 Claims. (Cl. 244153) ABSTRACT OF THE DISCLOSURE Thekite disclosed has a T-shaped frame with a cross bar at the front thatis approximately twice as long as the longitudinal member connectedrigidly and at right angles to the center of the front cross bar. Thesupporting surface is a sheet or film of flexible material having itsfront edge secured along the cross bar and its longitudinal centerconnected along the rearwardly extending longitudinal base of theT-shaped frame. The sail is slack along its side edges so as to balloonup in flight in symmetrically curved surfaces rearwardly of the frontcross member and laterally of the longitudinal axis of the kite. A tailsurface of self sustaining rigidity is secured in upwardly andrearwardly inclined position on the rear end of the longitudinal framemember.

Summary of invention The inventive ingenuity in the kite lies in therelationship between its parts, as outlined in the abstract ofdisclosure, which provides a kite having extremely stable, high flyingcharacteristics, combined with light weight and economy of production.The kite provides a high lift to drag ratio that adjusts automaticallyto different Wind conditions and permits the kite to be flown in lightwinds and air currents, and also permits the kite to glide down when thewind decreases.

The drawings of which there is one sheet illustrate a preferredembodiment of the kite.

FIGURE 1 is a top plan view of the kite in horizontal flight.

FIGURE 2 is a front elevational view of the kite in flight.

FIGURE 3 is a side elevational view of the kite in horizontal flight.

FIGURE 4 is a fragmentary cross sectional view taken along the plane ofthe line 44 in FIGURE 1.

FIGURE 5 is a fragmentary cross sectional view taken along the plane ofthe line 55 in FIGURE 1.

The kite consists of a T-shaped frame formed of a rigid transverse frontmember 1 connected at right angles to a rearwardly extendinglongitudinal bar or frame member 2 with the longitudinal memberconnected to the center of the transverse member and being approximatelyone-half the length of the transverse member. In practice the framemembers 1 and 2 are sticks of light wood and may be secured together asby adhesive indicated 3 in FIGURE 5. Secured along the undersides of theframe members 1 and 2 are sail members 4 and 5 formed of films or sheetsof flexible material such as light cloth, paper or plastic. The sailmembers have leading edges 6 that are secured to the transverse memberand longitudinal edges 7 that are secured continuously along thelongitudinal member and outer side edges 8 that are substantially longerthan the diagonal distance between the ends of the transverse member 1and the rear point of connection of the sail members to the longitudinalmember. This shape of the sail members is achieved by cutting or formingthe sail members in a plane surface as shown by the dotted line inFIGURE 1 in which the leading edges 6A extend forwardly at an obtuseangle to the longitudinal 3,412,964 Patented Nov. 26, 1968 ice inneredges of the sail members thus leaving slack in the outer side edges 8when the sail members are secured to the frame members. The particularreversely curved contour of the outer side edges 8 having convex curves9 and 10 at their ends joined by a concave curve 11 are optional butprovide a desirable birdlike appearance of the kite in flight. When thekite is in flight the slack in the sail members causes them to balloonupwardly in upwardly convex curved surfaces 12 that converge downwardlyalong the sides of the longitudinal member 2 and downwardly andforwardly to the front cross member 1.

Secured to the rear end of the longitudinal member 2 is a tail 13 oflight but shape retaining material such as the sheet of styrofoammaterial indicated in FIGURE 4. The tail 13 is conveniently removablymounted in place by providing a hole 14 through the tail through whichthe rear end of the longitudinal member 2 projects. A looped rubber band15 has its forward end secured to the underside of the longitudinalmember as by the staple 16 and passes downwardly through a slit or notch17 formed in the lower edge of the tail and then upwardly in a loop 18over the rear end of the longitudinal member to draw the lower end ofthe tail forwardly against the edges of the hole 14 and against apositioning block 19 secured to the underside of the longitudinalmember. The tail is thus positioned in an upward and rearward inclinedposition relative to the frame of the kite and projects above and belowthe frame with the larger portion of the area of the tail being exposedbetween the upwardly ballooned surfaces 12 of the sail members 4 and 5.

A connection indicated generally at 20 is provided on the underside ofthe longitudinal member for connecting a flying string 21 to the kite.For most stable operation of the kite, the connection 20 consists of ayoke of flexible material such as string having relatively short forwardarm 22 and a relatively long rear arm 23. The rear arm 23 may include alongitudinally yieldable section such as a rubber band 24 secured inplace by a staple 25. The front arm 22 is also conveniently attached tothe underside of the transverse member by a staple 26 (see FIG- URES 5and 6). The flying string 21 may be connected to the yoke by a swivelconventionally illustrated at 27.

Desirably the leading edges 6 of the sail members are detachably securedalong the underside of the transverse member 1 by means of a strip ofadhesive material 28 which overlaps the edge of the sail and theadjacent surface of the transverse member. This permits adjustment ofthe slack in the sail members to equalize the slack in each sail andprovide lateral stability to the kite. It is further convenient to makeboth sail members 4 and 5 from a single sheet of material and to attachthe longitudinal center of the combined sail members to the longitudinalframe member 2 by providing a series of holes 29 in the sail member. Asecond strip of adhesive material 30 is then placed along the undersideof the longitudinal member, passing through the holes 29 to adhere tothe longitudinal member at spaced points and hold the sail member ormembers in position.

The kite constructed as described above is capable of numerousvariations in proportion, shape and weight and these variations willvary the flight characteristics of the kite. Desirably the center ofgravity of the kite is positioned generally under the maximum balloonedportion of the sail members as at 31 in FIGS. 1 and 3 and the weight ofthe tail 13 is one-twelfth of the total weight of the kite. Within thisgeneral portion the weight of the tail may be relatively concentrated bymaking it of smaller area and greater thickness and this variation isdesirable for flying the kite in high wind velocity. A broader thinnertail is more desirable under light wind conditions. Regardless of therelative size of the tail the upwardly and rearwardly projectingposition of the tail as shown in full lines in FIGURE 3 permits the tailto be acted upon by rearward air flow between the sails to prevent thekite from nosing forward and diving. The full line position in FIG- URE3 thus illustrates one extreme position of flight of the kite while thedotted line position 13A illustrates another extreme position in whichthe kite will exert maximum lift by reason of the wind acting on theballooned sails and creating minimum drag on the tail in its horizontalposition.

Due to the minimum structure and light weight of the kite for any givensize or area of the sail members and the stabilizing effect of the tail,the kite can be flown to relatively high altitudes and lift a maximumamount of string 21 with which the kite is flown. The balancing effectof the tail 13 permits the kite to giide forwardly and downwardlywithout nosing over or stalling should the supporting air currentsdecrease in velocity.

What is claimed as new is:

1. A kite comprising a rigid central longitudinal member,

a rigid transverse member connected in crossing relation to saidlongitudinal member adjacent to the front end of the latter andcentrally of the transverse member,

sail members of flexible flat sheet material having central edgesconnected to said longitudinal member in flat coextensive relation fromsaid transverse member to a point adjacent the rear end of thelongitudinal member,

said sail members having leading edges that extend in forward obtuseangles from said central edges when the sail members are arranged in aplane and which are connected in straight continuous relation along saidtransverse member to adjacent the ends of the latter,

side edges on said sail members of greater length than the straight linedistance between the outer ends of said leading edges and the rear endsof said central edges and extending loosely therebetween,

a fiat tail member of self sustaining rigidity connected to saidlongitudinal member behind said sail members and disposed at an upwardlyand rearwardly inclined angle to the plane of said longitudinal and saidtransverse members,

and a connection for a string arranged to apply a downward force to saidlongitudinal member at a point spaced rearwardly of the transversemember.

2. A kite as defined in claim 1 in which said connection for said stringconsists of a flexible yoke having its ends connected to saidlongitudinal member in spaced relation on opposite sides of the centerof gravity of the kite,

and a string connection to said yoke located closer to the front of theyoke than the back.

3. A kite as defined in claim 2 in which said transverse member issubstantially longer than said longitudinal member.

4. A kite as defined in claim 3 in which said transverse member isapproximately twice as long as said longitudinal member,

and the string connection to said yoke hangs below a point between thecenter of gravity of the kite and the forward end of said longitudinalmember.

5. A kite as defined in claim 1 in which said tail is removably securedin place by means of a hole formed in a lower portion of the tailreceiving the rear end of the longitudinal member,

and a flexible band secured to the underside of the longitudinal memberand passed downwardly through a notch in the lower edge of the tail andlooped upwardly over the rear end of the longitudinal member.

6. A kite as defined in claim 1 in which the leading edges of said sailmembers are attached to said transverse member by strips of removableadhesive tape permitting adjustment of the slack in side edges of thesail members.

7. A kite as defined in claim 1 in which said side edges of said sailmembers have convexly curved ends joined by a concavely curved centralportion.

8. A kite as defined in claim 2 in which said sail members are made of asingle sheet of fiexible material having a line of holes formedtherethrough along the longitudinal axis thereof,

and a strip of adhesive material applied to said sheet along said lineand adhered to said longitudinal member through said holes.

9. A kite as defined in claim 2 in which said sail members are lapped onthe undersides of said longitudinal and transverse members,

and said tail projects above and below said longitudinal member with themajor proportion of the area of the tail above the longitudinal member.

10. A kite as defined in claim 2 in which the Weight of said tail isapproximately one-twelfth the total weight of the kite.

References Cited UNITED STATES PATENTS 1,690,362 11/1928 De Witt.

3,194,520 7/ 1965 Kurkjian. 3,250,500 5/1966 Hall.

FOREIGN PATENTS 4,230 1/1908 Great Britain.

MILTON BUCHLER, Primary Examiner.

P. E. SAUBERER, Assistant Examiner.

